Brent leaves extension and loft rights intact almost everywhere — and then refuses nearly a third of the larger rear extensions put to it through prior approval. What you can build here without full planning, where the council draws the line in practice, and why a certificate is worth more in this borough than in most.
No — and that is the easy half of the answer. Brent’s Article 4 direction is narrow, removing only the right to turn a family house into a small HMO on named streets around Wembley and Harlesden; extension and loft rights survive it everywhere. The harder half is what happens when you use the 6-metre route. Brent determined 794 larger householder extensions in the twelve quarters to March 2026 and refused 249 of them, 31.4%, against 24.9% across London. So the rights exist here, and this council polices their limits more closely than most. A 3-metre rear extension on a Kilburn terrace is straightforward; a 6-metre one is a decision, not a formality.
| What you want to do | Affected by Article 4? | Route |
|---|---|---|
| House to small HMO, named Wembley streets | Yes | Full planning |
| House to small HMO, named Harlesden streets | Yes | Full planning |
| House to small HMO, rest of the borough | No | Permitted development |
| Rear extension, anywhere in Brent | No | Permitted development, 3m / 4m |
| Loft conversion, anywhere in Brent | No | Permitted development, 40m³ / 50m³ |
| Anything in a conservation area | Separate restriction | Full planning |
Brent operates a street-level Article 4 for C3-to-C4 conversions rather than a borough-wide one, which is unusual in north-west London and is why a Brent address needs checking against the designation rather than the borough name. The conservation areas in Queen’s Park and Mapesbury are a separate constraint with its own effect on Class A. Verified against Brent Council’s published directions.
Without any application at all: a single-storey rear extension of 3 metres on an attached house or 4 on a detached one; a side extension up to half the original width and single storey; a loft conversion within 40 cubic metres on a terrace or 50 on a semi; an outbuilding inside the curtilage; and replacement windows and doors. Materials must match, a roof enlargement must sit 200mm back from the eaves, and nothing goes on a roof slope facing a highway. Doubling the rear depth to 6 metres is possible but is a different animal — it needs prior approval, the neighbours get to object, and in Brent roughly one in three of those is refused.
No, and in Brent that rules out a growing share of the borough. Permitted development under Schedule 2, Part 1 of the Town and Country Planning (General Permitted Development) (England) Order 2015 belongs to dwellinghouses. A flat or maisonette has none of it, whatever the lease says, so almost any external alteration needs a full application. Seventeen per cent of Brent's 135,080 homes have been built since 2010 and most of that is flats, which is why the question comes up so often here (VOA council tax stock, 31 March 2025).
Yes, sharply, but across a small part of the borough: 23 conservation areas covering roughly 350 hectares of 4,126. The largest are Queens Park, designated 30 June 1986 and covering 54.6 hectares; Mapesbury, 21 December 1982, 47.9 hectares; Sudbury Court, 1990, 44.1 hectares; and Barn Hill, 1 March 1990, 40.2 hectares. Twenty-two of the 23 carry a designation date in the open register and one does not, so we do not describe them as a fully dated set. Inside a boundary you lose side extensions, two-storey rear extensions, cladding and any enlargement of the roof, and removing a chimney needs permission.
An LDC is the council confirming in writing that what you propose is lawful without permission. The statutory fee is half a householder application, so £274 in 2026, plus the drawings. In Brent it is worth more than the fee suggests for two reasons. The council recorded 1,367 certificates over three years against 2,843 householder decisions, so it is a well-worn route here; and it served 399 enforcement notices in the same period, which is a lot, and an enforcement officer at the door is a much shorter conversation when you are holding a certificate. Worth knowing too: of 135 certificate appeals from Brent decided by the Planning Inspectorate between July 2016 and June 2026, 54 were allowed — 40.0%, against 36.9% for England. A refusal here is not the end of it.
Yes. These are two separate systems that happen to concern the same building. Permitted development answers the planning question only; building control still has to sign off structure, thermal performance, fire escape, drainage and ventilation, and it will inspect whether or not you ever spoke to a planning officer. On a Brent loft the fire-escape route is usually the item that changes the design, because the interwar semis that make up a fifth of the borough have a stair that opens straight into the living room. We prepare both the planning material and the building regulations drawings.



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Brent is split down the middle by age. A fifth of its homes are Victorian or older and another fifth went up in the 1930s, so the district you are in largely decides whether you are dealing with solid brick and cut rafters or cavity walls and a hipped roof. Fees quoted here are the statutory England rates for 2026, not our charges for the drawings.
| Postcode | Area | Dominant stock | What it means for a permitted development scheme |
|---|---|---|---|
| NW2 | Cricklewood / Neasden | Edwardian villas and terraces | Three authorities meet in NW2 around Cricklewood and Neasden — Brent, Barnet and Camden — which is settled from the property itself. |
| NW10 | Willesden / Harlesden / Kensal Green | Modern apartments, post-war estates | Willesden, Harlesden and Kensal Green share NW10 with Ealing, so the boundary is confirmed at the address before a prior approval is lodged. |
| HA0 | Wembley / Sudbury | 1930s semi-detached, new-build | HA0 covering Wembley and Sudbury lies wholly in the borough, so Brent validates and determines every prior approval sent from it. |
| HA9 | Wembley / Wembley Park | 1930s semi-detached, new-build | HA9 covers Wembley / Wembley Park only; Brent Council handles the permitted development scheme. |
| NW6 | Kilburn / West Hampstead / Queen's Park | Mansion blocks, post-war flats | NW6 is divided between Camden and Brent through Kilburn, West Hampstead and Queen's Park, and the deciding office follows the plot, not the district. |
| NW9 | Colindale / Kingsbury | Post-war flats, new-build | NW9 straddles a boundary: Colindale / Kingsbury addresses fall to Barnet Council or Brent Council, so confirm which authority validates the permitted development scheme before submitting NW9 drawings. |
Where the permitted route runs out, the full application in Brent is not a soft landing: the council granted 78.5% of householder applications in the twelve quarters to March 2026, below the London figure of 83.0%, refusing 612 of 2,843. It does decide quickly, though — 94.3% inside eight weeks against 92.5% across London.
Conservation areas and the withdrawal question: designation inside any of Brent's 22 areas removes permitted development, so the same scheme becomes a householder application at £548 over eight weeks instead of a £249 prior approval over six. What is worth knowing is how rarely that route ends in a retreat here: Brent received 6,430 applications and saw 193 withdrawn across the three years to last March, 3.0% against 6.9% for the 33 boroughs pooled (MHCLG planning statistics, retrieved 1 September 2026). Around Kensal Green and Harlesden the street elevation is what an officer reads first, and a scheme that answers it tends to be decided rather than pulled.
Article 4 and your Brent permitted development scheme: Article 4 for HMO conversions in specific streets around Wembley and Harlesden. At a NW2 address that matters twice over, because Brent Council applies the direction unevenly across Brent — we read the Brent policies map for the exact NW2 address before quoting permitted development schemes.
What Brent is built from: Edwardian villas in Queen's Park and Mapesbury; Victorian terraces in Kilburn and Harlesden; 1930s semi-detached in Wembley; post-war tower blocks in Church End. Highly diverse borough; Queen's Park and Mapesbury are heritage-controlled; Wembley is a major regeneration hub. That mix decides the permitted development scheme route in Brent more than the postcode does.
Sources for this Brent permitted development scheme page: borough policies maps and conservation-area registers (2025–26), Royal Mail postcode district boundaries, the Town and Country Planning (Fees for Applications) (England) Regulations, the Town and Country Planning (General Permitted Development) (England) Order 2015 as amended, and the Party Wall etc. Act 1996.

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